A Head Mounted Display (HMD) is a device worn on the head of a user with one or more portions of the device positioned in front of the user's eyes for displaying visual information. The front portion of the device is often opaque to occlude external vision or it may utilize a transparent or semi-transparent material to permit viewing the external world. HMDs are commonly comprised of a wearable housing, one or more micro displays to produce visual data, one or more collimating optical elements to visually transmit image data from the displays to the user and one or more speakers or headphones to transmit audio to the user. HMDs may contain a Head Tracking device to monitor the orientation of the user's head and change the display content based on any orientation changes. Two common display types are Liquid Crystal Displays (LCDs) and Organic Light Emitting Diodes (OLEDs) displays, each having their own benefits and drawbacks. LCDs, for example, must use a backlight to operate properly, whereas an OLED has the capacity to independently produce its own light. OLEDs generally require less power to operate, as the backlight of the LCD requires significant power consumption. OLEDs are also thinner than LCDs, allowing OLED-based devices to be more compact in size and shape. One drawback of an OLED, however, is that they generally have a shorter lifetime of operation.
HMDs typically employ either a monocular or binocular construction, where a monocular HMD transmits the image from a single display to a single eye of the user, while a binocular HMD includes two individual monoculars, one for each eye, with each monocular consisting of an eyepiece and a display. An HMD containing a single display may utilize an optical arrangement to simultaneously create two identical images from the single image and transmit each independent image to an individual eye. HMDs may use either a simple magnifier or compound microscope approach for its optical design. The simple magnifier approach, suitable for most HMDs, uses a single lens to visually transmit information from the display to user. The compound microscope approach uses two lenses and is used for more advanced HMDs.
A common limitation of existing HMDs is that they depend on separate electronic devices, such as PCs or mobile devices, to receive both power and audio/visual data. This often means that the HMD is physically tethered to a computer via one or more cables. Furthermore, existing HMDs do not provide, among other things, internal data storage capabilities, wireless communication capabilities, a computer processor or an operating system to run software programs specifically designed to utilize the unique capabilities of the HMD. While existing HMDs may be used to view content derived from computers and separate devices, they are typically so complex that the general public cannot easily use the HMDs. As a result, HMDs have yet to be adopted on a wide scale. Furthermore, widespread adoption of HMDs has been hampered by the lack of a HMD device that is specifically designed to support new media formats that can fully utilize the unique advantages a wearable HMD can offer, for example, immersive experiences using omnidirectional media.
Omnidirectional Media, such as panoramic images and video, contains image or video data that contains a substantially large field of view of a recorded environment. Omnidirectional media may be created using different methods, such as using a mirrored camera mount, a single camera, or multiple cameras with each camera pointed in a different direction for simultaneously recording image data from multiple angles. Multiple cameras may also be integrated into a single housing, containing both a battery and housing, allowing the device to be both self-powered and portable. These recording systems, also known as omnidirectional cameras, may be designed to capture a single photograph or full motion video. Omnidirectional cameras may also include multiple microphones with each microphone pointed in a different direction to simultaneously record audio data from different angles. In other words, a omnidirectional Camera may record both omnidirectional image data and corresponding omnidirectional audio data. An omnidirectional media file us considered “spherical” if its image data collectively contains a 360° degree horizontal field of view and a 180° vertical field of view. The visual format of an omnidirectional image may vary depending on the device or devices used to generate the omnidirectional image. A file containing omnidirectional image data may, for example, visually place the image data from each camera edge-to-edge or it may instead utilize a specialized process to visually transform and combine the image data from each camera into a single, unified image. One example of such an image is an equirectangular image, where the image data of two or more cameras have been transformed and seamlessly combined, or “stitched”, into a single combined image with a structural aspect ratio of 2:1 and image data containing a complete 360° horizontal by 180° vertical field of view.
At present, a user uses a software application known as an Omnidirectional Media Viewer (ODMV) in order to view a media file containing omnidirectional image data. ODMVs are specialized software applications for viewing omnidirectional media and are developed to operate on a number of different computing environments. For example, ODMVs may operate as desktop applications, web applications, or as mobile application for devices such as phones and tablets. Each ODMV may be specifically designed to support one or more omnidirectional media formats, such as the equirectangular format. A fundamental problem with the current ODMVs and other viewing solutions, however, is that they do not produce a deep sense of realistic immersion as one would in real life. This is because we do not naturally view the world around us through a small, distant window, like that of computer monitor, phone or tablet. Instead, we experience the world through our eyes and we can change what we see simply by moving our head. Due to these significant limiting factors, HMDs and ODMVs are not being embraced by consumers and the general public.